


The Wedding of the Decade

by hit_the_books



Category: Supernatural
Genre: Alpha Castiel (Supernatural), Alpha Castiel/Omega Dean Winchester, Alpha/Beta/Omega Dynamics, Alternate Universe - Royalty, Bottom Dean, Implied Mpreg, Knotting, M/M, Mild Smut, Omega Dean Winchester, Weddings, Witch Curses
Language: English
Status: Completed
Published: 2018-04-01
Updated: 2018-04-01
Packaged: 2019-04-16 21:11:01
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,884
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14173467
Author URL: https://archiveofourown.org/users/hit_the_books/pseuds/hit_the_books
Summary: It's the wedding of the decade.King Dean is marrying Prince Castiel. It's the kind of power Omega-Alpha couple thatOKandHellosalivate over.But neither Dean nor the press know Alpha Prince Castiel’s little secret... He turns into a merman whenever he gets wet.The honeymoon suite of the Hotel Milton has a hot tub to die for.It's going to be a very interesting honeymoon...





	The Wedding of the Decade

**Author's Note:**

> Count the tropes with me guys...
> 
> Royalty, a wedding, A/B/O *and* merman Cas!
> 
> I want to say thanks to my lovely beta [majesticduxk](https://archiveofourown.org/users/majesticduxk) for checking this fic over for me.
> 
> And I want to say thank you to the Tropefest mods for their lovely challenge and all the forms it takes - thanks Jojo and Muse C:

“You may kiss your omega,” the priest declared.

King Dean Winchester felt his heart flutter as Prince Castiel Shurley leaned in and gently pressed his lips to Dean’s. The alpha’s kiss sent a tingle down Dean’s spine, a warmth spreading throughout him as he breathed in Castiel’s soothing lavender, sea salt and pine bark scent.

As far as first kisses went, Dean was pretty damn sure it was the best anyone had ever had.

The congregation erupted in applause and cheers as Castiel pulled back and smiled at Dean, azure eyes taking Dean in, nose scenting the air. Castiel swallowed hard as he seemed to pick up on a change in Dean’s scent and Dean blushed, feeling the slightest hint of slick at his hole.

 _Oh man, we still need to get through the reception_ , Dean thought to himself as the recessional—Henry Purcell’s “Trumpet Tune”—started to play out over the cathedral’s organ. Being King of Terraria could buy much leeway, but to snub all their reception guests would be diplomatic suicide. Plus Sam, Eileen, Gabriel, Pamela, Benny, Bobby, Ellen and Jo would never let him live down missing his own wedding reception.

“Soon,” Castiel promised, voice only just loud enough for Dean as they glided through the cathedral. Dean’s state crown was heavy on his head, its plush velvet making him too warm. The ermine edged cape over his shoulders probably was not helping, but as soon as they were at the central royal residence for the reception, both Dean and Castiel would be able to dispense with some of the finery they had to wear as part of the ceremony. _Though Cas does look good in that coronet._

Dean suspected that Castiel would look good in just about anything or nothing, at least that was the conclusion he had come to during their carefully orchestrated courting that had lasted the past year. He was still keen to know just what Castiel looked like under all of his finery, the sight having been denied to him during each of their previous encounters. Though Dean would be the first to admit that Castiel looked good in a suit.

The two of them were escorted through a carefully laid out cordon, their public screaming and cheering outside the cathedral, the press busy taking photos and filming them. Led out to the closed, horse-drawn carriage that would transport them back to the palace, Dean raised his right hand and waved . A wall of noise hit him as his simple gesture further stoked the jubilation of his subjects.

Rufus, the head of Dean’s security detail loudly cursed and told Dean and Castiel to get in the carriage. Not wanting to get on Rufus’s bad side—the old man could hold a grudge—Dean got into the carriage on the right hand side as Castiel got in on the left. Once the two of them were in, the doors were closed and the horses urged on from standing to a trot.

Dean’s right wrist started to ache as he waved at his subjects while Castiel did the same.

“I’ve never seen such passion from the public before,” Castiel admitted, a hint of nervousness mingling with his regular alpha scent.

“I like to think it’s well deserved,” Dean supplied.

Castiel turned to look at Dean and smiled, “I am sure it is.”

***

“You must do us the honor of visiting next summer,” oozed one of the many princes of Damnea. Dean didn’t trust the alpha’s scent, but Azazel was well known as a skilled negotiator and so Dean remained polite, eyes darting around, looking for Castiel and an escape. While they had both changed into comfier attire, that did little to improve being in the company of some of their guests.

The reception had been going for hours and Dean was itching at this point to just get the honeymoon started. They had a night’s reservation for the Hotel Milton and then they would be flying out to some islands the the Winchesters owned towards the south of the kingdom.

A hint of Castiel’s scent wafted to Dean’s nose and he drew in a long steadying breath.

“I’m sorry,” interrupted Castiel, coming up behind Dean. “But Rufus says it’s time for us to depart.”

Dean gave a diplomatic smile to Azazel. “I will consider your invitation, but we do really need to go.”

“You let your staff order you around?” Azazel said with a contemptuous look.

Dean gave Azazel his own disdainful look. “I do, because they know _their_ job. Excuse us.”

Turning with Castiel, Dean led his alpha away and the two of them passed through the reception party, waving and smiling at more agreeable guests as they made their exit. It frustrated Dean to have to invite people like Azazel to events such as his wedding, but it would have been dangerous to snub the alpha’s family by sending no invite.

“Come, relax,” Castiel said in a soothing voice as the two of them sat in the back of the Bentley that had been sent for them.

The vehicle was large and majestic, though nowhere near as nice as the Chevy Impala 67 that was the jewel in Dean’s classic car collection. But unlike Dean’s Impala, the sleek Bentley was fitted with bulletproof glass and sides.

Dean sighed and nodded, taking reassurance in Castiel’s scent.

***

It felt so right to finally be alone for the first time. Truly alone. Dean felt a little light headed as anticipation and arousal flared through his body. Castiel had always been so charming and sweet, in each of their dates and meetings running up to their marriage, and while a part of Dean was skeptical that their marriage would be perfect—Dean was hopeful that Castiel really was it for him. The alpha smelled so good, _how can’t he be anything, but the one?_

“That’s a hot tub,” Castiel declared. The hot tub was set into the marble floor and was big enough for twelve people, which seemed an interesting design for a hot tub in a honeymoon suite.

“I know, Cas,” Dean said, smiling at the new nickname. He was completely naked and standing beside the bubbling water, and enjoying the effect his nakedness was having on Castiel, the alpha’s increasing arousal very easy to make out. Castiel’s thickening alpha cock was a solid visible line in his dress slacks, and his scent had intensified, a level of muskiness now added to it.

But despite Castiel’s arousal, he showed no signs of wanting to approach the inviting water. Dean wondered if maybe the prince had somehow never managed to experience one before. Unsure what the case may be, Dean climbed into the tub and signed happily as the bubble jets began to caress his buttocks and slowly filling omega cock.

Looking up at Cas from under his eyelashes, Dean gave his new husband the sauciest smile he could and said, “Come on in the, water’s fine.”

Cas gulped and looked like the inner battle within him was slowly giving way to Dean and biology, as he began to remove his clothes piece by piece. As if mesmerized, Cas stripped himself of his clothes, his aroused scent getting stronger with each item’s removal. Once naked, Dean licked his lips at the sight of Castiel’s cock standing to attention. Firm and leaking already.

Dean licked his lips again, wondering what it would be like to get his mouth on Cas.

Without any further preamble, Cas stepped to the hot tub and climbed in, crowding up against Dean instantly as his hormones took over. Dean’s eyes rolled backwards as Castiel’s mouth found his neck and sucked and licked at him, nosing at his scent gland, intent clear.

And then something splashed into the water, throwing water up into the air and spilling it over the sides of the tub, swamping the marble floor. Dean spluttered and pulled back Cas, opening his eyes.

A large, sapphire and emerald colored fishtail was splashing and churning the water. Cas was panting beside Dean, cheeks flushed. Eyes wandering, Dean glanced down into the water at Castiel’s torso and could clearly see the trail of colorful fish scales that showed the tail was a part of Castiel.

“Cas?” Dean asked in an unsure voice.

A sheepish look stole over Cas and the prince ( _merman?!_ ) looked away from Dean. “I suppose you would like an explanation?”

“Uh, yeah. That’s what you normally do when you pop a fishtail in a hot tub.” Dean pointed at the fishtail still swishing in the water.

“My family doesn’t know, please understand.”

“Doesn’t know what?”

“That I was cursed. As a boy, a witch cursed me for helping one of the servant’s children after the little girl got into trouble with the witch for stealing some of her apples.” Cas let out a long breath and his breathing evened out a little more.

“You were cursed, by a witch?” Dean wasn’t surprised. Witches, hags, enchantresses—such magic practitioners were rare, but he had heard of them.

“Yes. And I have tried to find a wat to remove the curse, for many years, but it just isn’t possible… I wouldn’t have gotten into the tub with you if you had not been so… divinely tempting.” Cas rubbed at the back of his neck.

“So, you turn into a merman whenever you come into contact with water, right?” Dean felt Castiel’s tail swish over his feet under the water.

“Well, not in rain. But a puddle that soaks my feet or trying to take a shower? Yes.” Cas gave Dean a nervous look and asked, “Of course if this is too much, we can call the whole marriage off. I just couldn’t risk telling you, I’m sorry to trick you, but you are… so… so much more than I could ever dare to hope for in a mate.”

Dean’s chest felt tight with emotion at hearing Castiel’s words. He was shocked, sure, but Dean could sense that Castiel was genuinely sincere in his words. “I’m sure… we can work around this,” Dean replied, taking his alpha into his arms. Bringing their lips together, the kiss gentle and reassuring, Dean tried to convey that he was not going to push Cas away.

Eventually they got out of the tub and dried Castiel off. In the generously sized bed of the Hotel Milton’s honeymoon suite, Dean and Castiel claimed each other, in every which way possible.

Stuffed with Castiel’s thick knot for the second time, pumped full, Dean allowed himself to be the little spoon as Cas stroked his belly.

“Cas… will our pups… you know?”

“If they do?”

Dean thought for a moment. “We’ll need to be careful about going on beach holidays.”

“You have your own private islands.”

“True.”

They laid on the bed in silence. Dean pushed closer to Cas, enjoying the tug of Castiel’s knot. “Still… not going to be able to have showers together.”

Cas nuzzled at the back of Dean’s neck. “Baths can be nice.”

The two of them chuckled at that. It would be an interesting royal marriage, with a rather unusual secret to keep between them, but as Dean breathed in the soothing scent of his mate, he knew tail or no tail—Cas was it for him.

**Author's Note:**

> I hope you enjoyed reading my fic. Kudos and comments are appreciated.
> 
> You can find me over on Tumblr at [dreamsfromthebunker](https://dreamsfromthebunker.tumblr.com/). I'm also on [Twitter](https://twitter.com/dreamsftbunker).


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